Volume II of the Fourth National Climate Assessment (NCA4) is expected to be released soon. Written by more than 300 scientists, this report comes from the congressionally mandated U.S. Global Change Research Program (USGCRP), which was created with the passage of the Global Change Research Act of 1990. Volume I of NCA4, the Climate Science Special

Volume II of the Fourth National Climate Assessment (NCA4) is expected to be released soon. Written by more than 300 scientists, this report comes from the congressionally mandated U.S. Global Change Research Program (USGCRP), which was created with the passage of the Global Change Research Act of 1990. Volume I of NCA4, the Climate Science Special

The average global temperature fluctuates every year. However, when you look at a snapshot of the global temperature trend, it's on the rise - particularly since 1970. The main cause? Carbon dioxide and other greenhouse gas emissions from human activities. There are plenty of factors that influence temperatures in different regions across the

The planet reached two important climate milestones this year. The globally averaged concentration of CO2 reached 400 parts per million, and the global average temperature climbed to more than 1°C (1.8°F) above pre-industrial levels for the first time since recordkeeping began.

Negotiators in Paris work on an international agreement to curb global warming as 2015 shapes up to be the hottest year on record. Climate Central's Chief Meteorologist Bernadette Woods Placky and Chris Field, climate scientist at Stanford University, report from COP21.

No matter how you stack it, the first half of the 2010s will be remembered for its record heat. The five-year period from 2011-15 has been the hottest such period ever recorded. And with last year setting the hottest year mark, only to be surpassed by a wide margin this year, it’s clear that the planet has changed. Ahead of the Paris climate talks

It is virtually certain that 2015 will be the warmest year on record, with one of the strongest El Ninos ever recorded combining with manmade warming to send global temperatures soaring. But which of these is more responsible for the record heat this year? Global warming fueled by the buildup of heat-trapping gases in the atmosphere is the

It’s about as sure a bet as you can make: 2015 is going to be the warmest year on record. Month after month this year, above-average — and sometimes record — global temperatures have piled up, raising the odds that this year will be the hottest one humanity has ever experienced. And now October has blown those records out of the water. According to